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Updated: Sep 10, 2026
A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Moderate alcohol intake and heart rate variability adaptations to high-intensity interval training in healthy young
Ginés Navarro-Lomas1, Alejandro De-la-O1, Manuel Dote-Montero1,2
1Department of Physiology, Faculty of Medicine, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain.
Background:
It is unknown whether daily alcohol consumption influences training effects on heart rate variability (HRV). This study investigated: (i) the effects of a 10-week high-intensity interval training (HIIT) on HRV in healthy young adults; and (ii) the effects of daily alcohol consumption on HRV responses to exercise.
Methods:
71 healthy young adults (18-40 years old; 52.1% women) participated in the BEER-HIIT study. We conducted a 10-week (2 days/week) controlled trial (ClinicalTrials.gov ID: NCT03660579). Participants were allocated to 5 groups: a non-training group (N-T) and four HIIT groups. Participants in the training groups chose whether to consume alcohol. Those choosing alcohol were randomly allocated to receive beer (5.4%; T-Beer) or an equivalent amount of alcohol (vodka; T-Ethanol) in sparkling water. Those choosing no alcohol were randomly allocated to receive alcohol-free beer (0.0%; T-Zero) or sparkling water (T-Water). Training comprised eight weight-bearing exercises performed in circuit form. HRV was measured before and after the intervention.
Results:
No statistically significant between-group differences in HRV outcomes were detected after the intervention (all p > 0.05).
Conclusions:
Our findings indicate that: (i) no statistically significant differences in HRV responses were detected following a 10-week HIIT program using weight-bearing exercises performed twice per week; and (ii) no statistically significant differences in HRV responses were observed among the assigned beverage intervention groups. These findings should be interpreted cautiously because HRV was a secondary outcome and the study was not specifically powered to detect differences in these parameters.
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